Internal combustion engines may be operated at least partly on gaseous fuel and may include gaseous fuel internal combustion engines and dual fuel internal combustion engines. In gaseous fuel internal combustion engines and dual fuel internal combustion engines, at least one gaseous fuel admission valve (e.g., gas admission valve), herein also referred to as gas admission valve, may be positioned between a source of gaseous fuel and a combustion chamber of the engine to control a flow of gaseous fuel into a combustion chamber, for example, via an air intake. For example, when a gas admission valve is opened, gaseous fuel may pass into the air intake for mixing with intake air.
Gaseous fuel may be premixed with the intake air and admitted into a cylinder to replace a required amount of diesel needed to achieve ratings and power demands. In this type of application, it is highly desirable to detect and respond if a failure has occurred in which too much gas is being premixed and sent to the cylinder to avoid undesirable operation or a catastrophic failure. More specifically, it is desirable to respond to any failure in the engine that could result in over fueling such as, but not limited to, the failure of a gas admission valve. It is desirable to have a mitigation strategy that may react as soon as a failure occurs, preventing undesirable operation of the engine or catastrophic failure to the engine.
In U.S. Pat No. 5,529,387, a solenoid operated orifice shut-off valve includes a piston head with a discharging orifice which is sealed by the pilot pin of a solenoid operated popper and a charging orifice by which high pressure fluid from the valve inlet is supplied. Solenoid actuated gas admission valves (SOGAVs) include a solenoid coil, a movable plate, and a stationary plate or disc, whereby a current delivered to the solenoid coil actuates the valve by lifting the movable plate from the stationary plate.
One problem which may arise in combustion engines utilizing a gas fuel admission valve includes an instantaneous load change, where the engine runs at relatively high load and then suddenly operates under a low load, the engine may over-speed and, consequently, the engine may completely shut down due to an inability to resume fuel injection.
Another problem that may arise is that the gas admission valve may open at undesirable times. For example, in the case of a solenoid actuated gas admission valve, a pressure difference between intake air and the gaseous fuel system may result in opening of the gas admission valve. As another example, small particulates may get trapped in the valve, for example, between the movable plate and the stationary plate or the seat of the solenoid actuated gas admission valve, and the valve may no longer close properly. As a further example, wear as well as contamination of the gas admission valve may result in leakage, increased pass rate, or even a stuck open gas admission valve. Other problems may similarly present issues in the operation of the gas admission valve.
These and other shortcomings of the prior art are addressed by the present disclosure.